CN215912273U

CN215912273U - Printed wiring board

Info

Publication number: CN215912273U
Application number: CN202121250647.1U
Authority: CN
Inventors: 林继生; 谢占昊; 邓杰雄
Original assignee: Shennan Circuit Co Ltd
Current assignee: Shennan Circuit Co Ltd
Priority date: 2021-06-03
Filing date: 2021-06-03
Publication date: 2022-02-25
Anticipated expiration: 2031-06-03

Abstract

The utility model discloses a printed wiring board, comprising: a substrate; the connecting layer is arranged by attaching one side of the connecting layer to one side of the substrate; the metal block is attached to the other side of the connecting layer; the connecting layer comprises a conductive part and a heat conducting part, and two opposite sides of the conductive part and the heat conducting part are respectively attached to the substrate and the metal block. Through the structure, the printed circuit board comprises the conductive part and the connecting layer of the heat conducting part, and the substrate and the metal block are connected together, so that the requirements of conducting electricity and conducting heat on the interface of the substrate are met.

Description

Printed wiring board

Technical Field

The utility model is applied to the technical field of printed circuit boards.

Background

Pcb (printed Circuit board), also known as printed Circuit board or printed Circuit board, is an important electronic component used in a wide range of applications, is a support for electronic components, and is also a carrier for electrical connection of electronic components. Printed circuit boards are widely used in various electronic products. At present, with the integration of electronic product functions, the structure of the printed circuit board is developing towards higher density, and the demand for heat dissipation is also developing towards higher direction.

At present, the heat dissipation mode of the printed circuit board is usually carried out by embedding a metal block or pasting a metal block on the surface of the metal block. However, when the metal block is attached to the surface, the metal block and the surface of the printed circuit board need to be adhered by a glue layer to realize fixed connection, so that the heat dissipation effect of the heat dissipation mode of attaching the metal block to the surface is affected.

SUMMERY OF THE UTILITY MODEL

The utility model provides a printed circuit board, which aims to solve the problem that the heat dissipation effect of a heat dissipation mode of sticking a metal block on the surface is influenced by an adhesive layer in the prior art.

In order to solve the above technical problem, the present invention provides a printed wiring board, including: a substrate; one side of the connecting layer is attached to one side of the substrate; the metal block is attached to the other side of the connecting layer; the connecting layer comprises a conductive part and a heat conduction part, and two opposite sides of the conductive part and the heat conduction part are respectively attached to the substrate and the metal block.

Wherein, the heat conducting part is provided with at least one through hole; the conductive part is accommodated in the through hole.

The conductive part is attached to the inner wall of the through hole.

The shape of the through hole comprises at least one of a rectangle, a circle, a triangle, a circular ring and a diamond.

Wherein the ratio of the opening area of the through hole to the area of the connecting layer is in the range of 10-60%.

The heat conducting part comprises at least one of a low-flow adhesive film, a prepreg or a composite graphene conductive adhesive film.

The conductive part comprises at least one of conductive adhesive film, silver paste or copper paste.

The substrate is provided with at least one first via hole, the connecting layer is provided with at least one second via hole, and the metal block is provided with at least one blind hole; the first via hole, the second via hole and the blind hole are correspondingly arranged and have the same aperture; wherein components are arranged in the correspondingly arranged first via hole, the second via hole and the blind hole.

One side of the component is electrically connected with the bottom of the blind hole through a welding layer.

And the other side of the component is electrically connected with the other side of the substrate through a lead.

The utility model has the beneficial effects that: different from the situation of the prior art, the printed circuit board realizes the connection between the metal block and the substrate by arranging the connection layer comprising the conductive part and the heat conduction part, thereby not only realizing the fixation between the metal block and the substrate, but also ensuring the heat conduction and the electric conduction between the metal block and the substrate, leading the metal block to well exert the functions of heat dissipation or electric communication, and improving the quality and the reliability of the printed circuit board.

Drawings

FIG. 1 is a schematic structural diagram of one embodiment of a printed wiring board of the present invention;

fig. 2 is a schematic cross-sectional view of the connecting layer 12 in the embodiment of fig. 1.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a printed wiring board according to an embodiment of the present invention. The printed circuit board of the embodiment adopts a heat dissipation mode of sticking a metal block on the surface to dissipate heat.

The printed wiring board 10 includes a substrate 11, a connection layer 12, and a metal block 13. The connecting layer 12 is disposed corresponding to the metal block 13, specifically, one side of the connecting layer 12 is disposed to be attached to the substrate 11, and the other side of the connecting layer 12 is disposed to be attached to the metal block 13.

The substrate 11 of this embodiment includes at least one of a plurality of types of printed circuit boards, such as a single-layer printed circuit board, a multi-layer printed circuit board, a single-sided printed circuit board, a double-sided printed circuit board, or a flexible printed circuit board, and the specific type thereof may be set based on actual requirements.

In this embodiment, a connection layer 12 and a metal block 13 are correspondingly disposed on the substrate 11. However, in other embodiments, two or more connection layers 12 and two or more metal blocks 13 may be correspondingly disposed on the substrate 11. For example: 3, 5, 7, 10, etc., which may be specifically set based on actual requirements, and are not limited herein.

The connection layer 12 includes a conductive portion 122 and a thermal conductive portion 121, the conductive portion 122 is for conducting electricity between the substrate 11 and the metal block 13, and the thermal conductive portion 121 is for conducting heat between the substrate 11 and the metal block 13. Specifically, opposite sides of the conductive portion 122 and the heat conduction portion 121 are respectively attached to the substrate 11 and the metal block 13, so that heat conduction and electric conduction are performed between the substrate 11 and the metal block 13.

Through the structure, the connection between the metal block and the substrate is realized by the connecting layer comprising the conductive part and the heat conducting part, so that the fixation between the metal block and the substrate is realized, the heat conduction and the electric conduction between the metal block and the substrate are ensured, the function of heat dissipation or electric communication of the metal block can be well played, and the quality and the reliability of the printed circuit board are improved.

In other embodiments, the metal block 13 may include a conductive metal block with heat dissipation properties, such as a copper block, a silver block, or an aluminum block after electroless nickel-gold processing, so as to achieve the function of facilitating heat dissipation of the substrate 11.

In other embodiments, at least one through hole (not labeled) is disposed on the heat conducting portion 121, and the at least one conductive portion 122 is received in the at least one through hole.

In a specific application scenario, the whole heat conducting portion 121 may be milled to form at least one through hole on the heat conducting portion 121, and then at least one conductive portion 122 having the same thickness as the heat conducting portion 121 is placed in the through hole, so that two opposite sides of the conductive portion 122 are flush with two opposite sides of the heat conducting portion 121, and it can be ensured that the two opposite sides of the conductive portion 122 and the heat conducting portion 121 are respectively in contact with the substrate 11 and the metal block 13, thereby obtaining the connection layer 12 of the embodiment.

Since the opposite sides of the conductive portion 122 are flush with the opposite sides of the heat conduction portion 121, when the conductive portion 122 and the heat conduction portion 121 connect the substrate 11 and the metal block 13, heat and electricity can be favorably conducted between the substrate 11 and the metal block 13.

In other embodiments, the conductive portion 122 is attached to the inner wall of the through hole, so that the conductive portion 122 is attached to the thermal conductive portion 121, the electrical and thermal conductive effects of the connection layer 12 are improved, and the quality of the printed circuit board 10 is ensured.

In other embodiments, the shape of the through hole on the thermal conduction portion 121 includes at least one of a rectangle, a circle, a triangle, a circular ring, and a diamond, and the shape of the conductive portion 122 corresponds to the same shape of the through hole. And the shapes of the through holes may be different from each other. The through holes can be partially connected into a piece.

In other embodiments, the ratio of the opening area of all the through holes to the area of the connection layer 12 is in a range of 10% to 60%, and the specific ratio may be in a range of 10%, 15%, 20%, 25%, 31%, 35%, 42%, 46%, 49%, 53%, 57%, 60%, or the like. The number of the through holes on the heat conduction portion 121 may be multiple, for example, 4, 8, 10, etc. The higher the area of the area, the higher the electrical conductivity between the substrate 11 and the metal block 13.

In other embodiments, the thermal conductor 121 includes at least one of thermal conductive materials such as low-flow adhesive film, prepreg, or composite graphene conductive adhesive film. The composite graphene conductive adhesive film also has a conductive function, and when the heat conduction part 121 is the composite graphene conductive adhesive film, the heat conduction part 121 can realize both the conductive function and the heat conduction function. And the low-flow adhesive film, the prepreg or the composite graphene conductive adhesive film and other heat conducting materials have low cost, and the low-flow adhesive film, the prepreg or the composite graphene conductive adhesive film and other heat conducting materials are adopted as the heat conducting part 121, so that the manufacturing cost of the printed circuit board 10 can be reduced, and the economic effect of the printed circuit board 10 is improved.

In other embodiments, the conductive portion 122 includes at least one of a conductive adhesive film, a silver paste, or a copper paste. The conductive adhesive film is generally composed of a resin matrix, conductive particles, a dispersing additive, an auxiliary agent and the like, and the filler particles having both the electric conduction and the heat conduction functions are generally powders of gold, silver-coated copper and the like. However, since the conductive particles of the conductive adhesive film are expensive, if the conductive adhesive film is used as the entire connection layer 12, the cost of the printed wiring board 10 is greatly increased. And the conductive adhesive film has low heat resistance, poor chemical resistance and toughness, and the performance and the service life of the printed wiring board 10 are influenced when the conductive adhesive film is used in the printed wiring board 10 for a long time.

In a specific application scenario, a conductive film having the same thickness as the connection layer 12 may be bonded in the through hole milled from the connection layer 12, and the size of the conductive film is close to the milled empty area, so as to form the conductive portion 122. At this time, the connection layer 12 conducts electricity and conducts heat to a certain extent through the conductive part 122 of the conductive adhesive film, so that the use of the conductive adhesive film can be saved, the production cost can be reduced, the heat conduction and the electricity conduction between the substrate 11 and the metal block 13 can be ensured, and the quality of the printed circuit board 10 can be guaranteed.

In another specific application scenario, a conductive medium such as silver paste or copper paste with conductive property may be printed or coated in the through hole milled in the connection layer 12 to form the conductive portion 122. Finally, the heat and electricity conducting function of the interface is achieved, and the purpose of saving the use cost of the conductive adhesive is achieved.

Therefore, in the present embodiment, the connection layer 12 is formed by combining the heat conducting portion 121 and the conducting portion 122, so that not only can the substrate 11 and the metal block 13 be fixed, but also the electric conduction and the heat conduction between the substrate 11 and the metal block 13 can be realized, the manufacturing cost of the printed wiring board 10 can be reduced, the economic effect of the printed wiring board 10 can be improved, the performance of the printed wiring board 10 can be improved, and the service life of the printed wiring board 10 can be prolonged.

In other embodiments, the substrate 11 is provided with at least one first via hole 143, the connection layer 12 is correspondingly provided with at least one second via hole 123, and the metal block 13 is correspondingly provided with at least one blind hole 131, wherein the first via hole 143, the second via hole 123 and the blind hole 131 which are correspondingly provided have the same aperture; the component 14 is commonly accommodated in the first via hole 143, the second via hole 123, and the blind hole 131, which are correspondingly provided.

The component 14 may include any component such as a chip, an integrated circuit, an electroacoustic device, or a sensitive device, and the specific type of the component 14 is not limited herein.

In other embodiments, one side of the component 14 is electrically connected to the bottom of the blind via 131 through the solder layer 142 to achieve the function of the component 14.

In a specific application scenario, a tin sheet can be placed between one side of the component 14 and the bottom of the blind hole 131, and the component is pressed and heated, so that the tin sheet is heated and pressed to melt and flow to fill gaps among the component 14, the metal block 13 and the substrate 11, and a welding layer 142 is formed, thereby achieving the purpose of integrally welding and fixing the component 14, the metal block 13 and the substrate 11.

In other embodiments, the other side of the component 14 and the other side of the substrate 11 may be electrically connected by a wire 141 to implement the function of the component 14.

Referring to fig. 2, fig. 2 is a schematic cross-sectional view of the connection layer 12 in the embodiment of fig. 1.

The connection layer 12 of the present embodiment includes a heat conduction portion 121, and the heat conduction portion 121 is provided with a plurality of through holes and at least one second via hole 123. Wherein the plurality of through holes respectively accommodate therein the conductive portions 122. The thermal conductive portion 121 is attached to the plurality of conductive portions 122 to form the connection layer 12.

Further, the connection layer 12 is further provided with a second via hole 123, and the component 14 is partially accommodated in the second via hole 123.

In the present embodiment, the shape of the through hole and/or the conductive portion 122 is a square, but in other embodiments, the shape of the through hole and/or the conductive portion 122 may be any other shape.

In the present embodiment, a plurality of through holes and/or conductive portions 122 are disposed around the second via hole 123 to improve the uniformity of electrical and thermal conduction between the metal block 13 and the substrate 11, thereby improving the quality and reliability of the printed wiring board 10. In other embodiments, the through hole and/or the conductive portion 122 may be a single circular ring, and the circular ring may be disposed around the second via hole 123 with the second via hole 123 as a center, so as to improve the uniformity of electrical and thermal conduction between the metal block 13 and the substrate 11, and thus improve the quality of the printed wiring board 10. The specific position of the plurality of through holes and/or the conductive portions 122 on the connection layer 12 is not limited herein.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A printed wiring board, characterized in that the printed wiring board comprises:

a substrate;

one side of the connecting layer is attached to one side of the substrate;

the metal block is attached to the other side of the connecting layer;

the connecting layer comprises a conductive part and a heat conduction part, and two opposite sides of the conductive part and the heat conduction part are respectively attached to the substrate and the metal block.

2. The printed wiring board of claim 1, wherein the heat conducting portion is provided with at least one through hole;

the conductive part is accommodated in the through hole.

3. The printed wiring board of claim 2, wherein the conductive portion is disposed in abutment with an inner wall of the through-hole.

4. The printed wiring board of claim 2, wherein the shape of the via hole comprises at least one of a rectangle, a circle, a triangle, a donut, a diamond.

5. The printed wiring board of claim 2, wherein a ratio of an opening area of the through-hole to an area of the connection layer is in a range of 10-60%.

6. The printed wiring board of claim 1, wherein the thermal conductor comprises at least one of a low flow adhesive film, a prepreg, or a composite graphene conductive adhesive film.

7. The printed wiring board of claim 1, wherein the conductive portion comprises at least one of a conductive adhesive film, a silver paste, or a copper paste.

8. The printed wiring board of any of claims 1-7, wherein at least one first via hole is provided in the substrate, at least one second via hole is provided in the connection layer, and at least one blind hole is provided in the metal block; the first via hole, the second via hole and the blind hole are correspondingly arranged and have the same aperture;

wherein components are arranged in the correspondingly arranged first via hole, the second via hole and the blind hole.

9. The printed wiring board of claim 8, wherein one side of the component is electrically connected to the bottom of the blind via by a solder layer.

10. The printed wiring board of claim 9, wherein the other side of the component is electrically connected to the other side of the substrate by a wire.